Process for preparing lubricating oil additive and products



United States PatehtO PRGCESS FOR PREPARING LUBRICATING OIL ADDITIVE AND PRODUCTS John M. Musselman, South Euclid, and Richard E. Knowlton, Warrensville Township, Cuyahoga County, Ohio,

assiguors to The Standard Oil Company, Cleveland,

Ohio, a corporation of Ohio No Drawing. Application July 28, 1952,

Serial No. 301,366

15 Claims. (Cl. 252-32.7)

This invention relates to compositions suitable as lubricants and lubricant additives and having a high alkaline reserve especially adapting them for use in engines designed to operate on fuels having a high sulfur content and to a process for preparing such lubricants and lubricant additives.

In diesel engines lubricating oil life has been highly limited by contamination from soot, dust and oxidation products, as Well as by dilution. A high degree of corrosive cylinder wear also results from the use of sulfurbearing fuels. Heavy duty lubricating oils have overcome the problems of engine deposits and piston cleanliness to a certain extent, but have not been able fully to protect the engines from undue wear under corrosive conditions.

Edgar, Plantfeber and Bergstrom, SAE Quarterly Transactions, Society of Automotive Engineers, vol. 3, No. 3, page 381, July 1949, have shown that corrosive wear is connected with a premature depletion of the alkalinity of the lubricating oil additive. During the alkaline life of the additive protection from corrosive wear is satisfactory, but after the oil has become acid, protection largely disappears. This suggests that the protection afforded by the additive is due largely to a neutralizing effect on the acidic sulfur compounds coming from the combustion of the fuel. From this it logically has been concluded that a greater neutralizing effect would be obtained if an increased proportion of the alkaline detergent lubricating oil additive were present in lubricating oils intended for use in diesel engines. Massive doses of additives have been added to lubrieating oils, using an appropriate balance of anti-oxidant, anti-corrosion and detergent additives. Such special heavy duty oils are described in Special Technical Publication N0. 102, Symposium on High Additive Content Oils, published for the American Society for Testing Materials, dated October 12, 1949. These oils are said to have nullified the corrosive cylinder wear which heretofore had resulted from the use of sulfur-bearing fuels in diesel engines. Piston fouling was also reduced or eliminated, with commensurate increases in oxidation stabiilty, protection of alloy bearings and improved heat resistance. However, a precise balance of additive proportions was found to be absolutely requisite. Traditionally, high concentrations of detergent additives in lubricating oils have been disapproved, for high concentrations of such substances may produce deposits in combustion chambers and/or on valves. Additives are not inexpensive, and with massive doses their cost becomes more important. The use of massive doses of lubricating oil additives thus in every situation may not be a practical solution to this problem. An additive especially designed or tailored to meet the problem when used in small or normal doses would fill a definite need in this field.

In accordance with this invention, a lubricating oil detergent additive is provided which is characterized by a high alkaline reserve, such that increased protection against corrosive wear due to acids is provided in use at the normal level of additive concentration in lubricating oils. Thus the problem is attacked from the standpoint of increasing the alkaline reserve of the additive at normal concentration, as distinguished from an increase in the concentration in the oil of an additive of normal alkalinity. I

Metal derivatives of phosphorus sulfide-organic compound reaction products are known to be useful as detergent additives for lubricating oils. These materials are prepared by neutralization of phosphorus sulfide organic compound reaction products with a metal compound, usually the hydroxide. Even when fully neutralized to a saponification number of zero, however, such products While having an alkalinity sufficient for most purposes are not sufiiciently alkaline to meet the special requirements of engines used with high sulfur content fuels. Moreover, the completely saponified metal derivative sometimes has a low oil solubility and therefore may not be desirable in an oil. In some instances this product is a solid gel. The partially saponified product has a good oil solubility but an insufiicient alkaline reserve.

By the process of the invention, a completely saponified phosphorus sulfide-degras reaction product is provided which retains the oil solubility of the partially saponified reaction products and yet has a higher alkaline reserve than the completely saponified reaction product. This product is obtained by reacting a partially saponified oil-soluble phosphorus sulfide-degras reaction product with an alkaline earth compound and an alkyl phenol, continuing the reaction until the reaction product has reached a high base number, usually of the order of 30 to 86 or more. The term base number as used herein is as defined in ASTM D664-46T.

In general outline, the process of the invention includes the preparation of a reaction product of a phosphorus sulfide and degras at a temperature below sludge formation to produce an acidic reaction product, a primary saponification of this reaction product with an alkaline earth compound to a stage short of complete saponification at which the partially saponified reaction product retains an appreciable oil-solubility and a secondary saponification of the partially saponified reaction product in the presence of an alkyl phenol with an alkaline earth compound which is continued until the reaction product has a high base number.

Any phosphorus sulfide or mixture of phosphorus sulfides is reactive with degras. Phosphorus pentasulfide P285 is most readily available and least expensive, and for this reason is used in the illustrative examples and would most usually be employed. However, other phosphorus sulfides can be used.

Degras is a crude grease obtained by washing sheeps wool, and contains several components reactive with phosphorus sulfides. Degras itself and fractions derived therefrom and reactive with phosphorus sulfides can be used, and the term degras as used herein is inclusive both of the mixture and fractions or components derived therefrom.

The metal derivative of the phosphorus sulfide-degras reaction product can be formed from one or more alkaline earth compounds capable of reacting with an acid hydrogen atom of the phosphorus sulfide-degras reaction product with formation of water, such as the metal oxides, hydroxides, carbides and cyanamides. The hydroxides are preferred for their availability and their low cost, as well as their high alkalinity. Barium, calcium, strontium and magnesium oxides, hydroxides, carbides and cyan.- amides can be used, barium hydroxide being preferred.

The alkali metal derivatives as distinguished from the alkaline earth metal derivatives are not oil-soluble and do not possess a base number sufficiently high for the purposes of the invention and, therefore, alkali metal compounds are not employed in forming the metal derivatives of the invention.

The alkyl phenols employed in accordance with the invention have the following general structure:

where R is a saturated or unsaturated straight or branched chain alkyl group, and may be ortho, meta, or para to the phenolic hydroxyl group. The number of carbon atoms in the alkyl chain is not critical but the alkyl chain should be long enough to impart oil solubility to the final product. This condition usually is satisfied by groups having from six to ten carbon atoms but much higher alkyl groups, for instance, up to twenty carbon atoms, can be present. The phenols having longer alkyl chains react more slowly, and the upper limit of carbon atoms in the alkyl group will be reached when the rate of reaction of the alkyl phenol has become so slow as to make the process impractical. The para alkyl phenols and especially the octyl phenols are preferred, particularly tert-octyl phenol which has the structure:

CH3 CH3 no b-onz-d-oni Typical alkyl groups include n-hexyl, isohexyl, heptyl, n-octyl, isooctyl, sec-octyl, tert-octyl, nonyl, tert-monyl, n-decyl, n-undecyl, n-dodecyl and 2-ethyl octyl. This list obviously is not all inclusive and many other alkyl groups which could be used are known to those skilled in the art.

The initial phosphorus sulfide-degras reaction product is prepared by reacting any amount of phosphorus sulfide, up to approximately 27% by weight of the reaction mixture, with the degras at a temperature below sludge formation. Sludge contains phosphorus, largely, and is undesirable because it represents a loss of phosphorus which might otherwise be in the desired reaction product. The product should have a maximum phosphorus and sulfur content, especially phosphorus, because the larger the phosphorus content the greater the acidity of the product and the more base with which it will react to yield a final product of high alkaline reserve. In order to prevent the formation of sludge, it is desirable to use the highest temperature commensurate with the above considerations so as to complete the reaction in the shortest possible time. However, the smaller the amount of phosphorus sulfide used, the higher the reaction temperature can be without danger of sludge formation. Thus, where 25% phosphorus pentasulfide is used, the preferred reaction temperature is about 225 F. When phosphorus pentasulfide is used, a temperature of 250 F. will not result in the formation of sludge.

The phosphorus sulfide will dissolve as the reaction proceeds. If an excess of phosphorus sulfide is employed, it will not react with the degras and the excess will have to be filtered out. Thus the upper limit of phosphorus sulfide employed is determined by the amount of phosphorus sulfide which will react with the degras and usually this upper limit will be approximately 27%. The preferred proportion of phosphorus sulfide is from to with the aim of producing an additive having as high a concentration of phosphorus as possible.

The reaction of phosphorus sulfide with degras will be complete when the phosphorus sulfide has completely dissolved in the reaction mixture. This will normally require about one hour. However, the reaction could be continued for a somewhat longer time if desired, since in most instances sludge will not form until after the reaction has been continued for from two to three hours. The reaction is stopped by lowering the temperature of the reaction mixture, which can be done simply from the contact with the filtering means used in filtering the reaction mixture.

The phosphorus sulfide can be added all at once if the contents of the reaction vessel are stirred rapidly. The phosphorus sulfide also can be added slowly in small portions in order to control the evolution of hydrogen sulfide in the course of the reaction.

A diluent which does not enter into the reaction can be added in order to slow down the reaction and reduce the viscosity of the reaction mixture. In some instances a diluent is needed in order to slow down the reaction to the extent required to avoid sludge formation before the reaction can be stopped. In the presence of a diluent, the reaction is easier to control. Satisfactory diluents are mineral lubricating oils, such as solvent-extracted neutral oils and acid-treated Mid-Continent lubricating oil base stocks of low viscosity.

The final saponification number of the phosphrous sulfide-degras reaction product will vary with the amount of phosphorus sulfide employed. In the case of a phosphorus pentasulfide-degras reaction product as a 34% solution in solvent-extracted neutral oil diluent, when 15 phosphorus pentasulfide is used, the saponification number will be about 55, when 20% phosphorus penta* sulfide is used, the saponification number will be about 65 and when 25% phosphorus pentasulfide is used the saponification number will be about 75.

The acidic phosphorus sulfide-degras reaction product obtained as described above then is given a preliminary or primary saponification, in which it is treated with an alkaline earth compound to lower its saponification number, but arresting the saponification reaction short of the point at which the product becomes oil-insoluble. Usually the saponification number can be lowered by from 50 to 80% without rendering the product oil-insoluble in this stage. As the saponification number is lowered by more than 80%, the product becomes increasingly difficult to filter. On the other hand, if the saponification number is not lowered by as much as 50%, the product may begin to sludge, as in the case when the initial reaction is carried appreciably beyond the point at which the phosphorus sulfide dissolves in the degras.

Bearing this in mind, an amount of alkaline earth compound theoretically required to lower the saponification number of the reaction product to the desired extent, plus a slight excess to drive the reaction to this point, is required in the primary saponification stage. The reaction temperature of the primary saponification is not critical and temperatures within the range from to 250 F. usually would be employed, although much higher temperatures, up to 350 F. could be used if desired. The further the primary saponification step is carried, the greater the excess of alkaline earth compound required to drive the reaction to the extent (short of completion) that is desired.

The secondary saponification is carried out in the presence of an alkyl phenol. The alkyl phenol is added to the reaction mixture only after the primary saponification has been completed, as determined by following the reduction in saponification number. However, it may be possible to add the total amount of alkaline earth compound required for both the primary and secondary saponification steps at the start of the primary saponification, with the alkyl phenol being added upon completion of the primary saponification reaction. When this is done, however, the progress of the saponification must be carefully followed to make sure that the alkyl phenol is added before the saponification has proceeded too far. Usually it is easier to control the extent of the primary saponification by adding initially only the amount of alkaline earth compound required for this step and then adding the alkyl phenol and an additional portion of alkaline earth compound, together or separately, at the start of the secondary saponification.

The amount of alkaline earth compound employed in the secondary saponification step is at least that theoretically required to completely neutralize the primary saponification product and the alkyl phenol. Any amount of alkyl phenol will improve the final product. That is, in the presence of alkyl phenol, it will be possible in the secondary saponification to obtain a final product having a higher base number than would be obtainable in the presence of the alkaline earth compound alone. When amounts of alkyl phenol in excess of approximately 10% by weight of the primary saponification product are added, the base number of the final product is not appreciably increased, and thus this amount approaches the practical upper limit of alkyl phenol that would be employed, from the standpoint of obtaining a useful result. However, larger amounts of alkyl phenol can be used if desired since an excess will not harm the final product.

The temperature at which the secondary saponification is carried out is not critical and any temperature within the range of about 150 to 400 F. can be used. The reaction mixture should be held at a relatively low temperature while the water liberated in the course of the saponification boils off. After this, the temperature can be considerably increased. At the higher reaction temperatures, some reduction in oil-insolubility or the production of oil-insoluble materials may result and for this reason temperatures in excess of approximately 300 F. will not usually be used.

The final product obtained in accordance with the above-described procedure has a base number of 30 to 86 or even more, indicative of its high alkaline reserve and excellent detergent properties. It is, therefore, useful both to combat acidity resulting from high sulfur fuels and as a detergent additive for lubricating oils, and the lubricants thus obtained can be used in gasoline, natural gas and diesel engines. This additive tends, however, to be poor in oxidation inhibition, and in use would, therefore, usually be employed in conjunction with an antioxidant lubricating oil additive. .ln order to furnish a lubricating oil having balanced antioxidant and additive properties, any available antioxidant additive can be used, for instance: high temperature reaction products of phosphorus pentasulfide and degras, and the barium derivative thereof, of phosphorus pentasulfide and hydrogenated sperm oil and the barium derivative thereof, Lubrizol 309 (believed to be a commercial zinc di thiophosphate lubricating oil additive), and CPS No. 69 (believed to be a commercial sulfurized terpene lubricating oil additive). The combination of the additive of the invention and an antioxidant lubricating oil additive with a motor oil produces a lubricant having a high alkaline reserve which will not develop hydrogen sulfide and which tends to improve wear properties.

The following examples are illustrative:

EXAMPLE I PREPARATION OF ADDrTIvE Degras (32.5 parts) and 80.1 parts of solvent-extracted neutral oil 150 SSU were charged to a reaction vessel. Over a period of about one and one-half hours the temperature was brought to about 225 B, after which a slurry of 8.1 parts of phosphorus pentasulfide and 17.4 parts of the solvent-extracted neutral oil were slowly charged to the reactor over a forty-five minute period with vigorous stirring. The reactor was maintained at 225 F. for approximately one hour, after which all of the phosphorus sulfide had dissolved and no sludge was formed. The product was filtered with the aid of 2% by weight of Special Speed Flow diatomaceous earth filter aid. The saponification number of the filtrate was 70.14 and its OD color was 920..

PREPARATION OF PRIMA Y SAPONIFICATION PRODUCT The filtrate (4000 parts) was returned to the reactor and heated to 150 F. Barium octahydrate (800 parts-562 parts theoretically required to reduce the saponification number to 20 plus a 30% excess) was added slowly over a fifteen minute period, after which the mixture was heated to 200 F. for one hour then to 250 F. for about one-half hour. During the last ten minutes the mixture was air-blown. Thereafter, the product was filtered with 5% Special Speed Flow filter aid. The filtrate had a saponification number of 19.75 and an OD color of 575. The yield was approximately 90%. The product was completely oil-soluble.

PREPARATION OF SECONDARY SAPoNIFIcATIoN PRODUCT The primary saponification product (400 parts) was charged to a reaction vessel and heated to 150 F. Barium octahydrate (Ba(OH)2-8H2O) (74 parts-40 parts theoretically required to reduce the saponification number to zero, plus a 78% excess, plus 34 parts theoretically required to neutralize the octyl phenol) was added over a period of fifteen minutes withcontinuous stirring followed by the addition of 44 parts of tert-octyl phenol. The reaction mixture then was heated to 300 E, which required about one and one-half hours, holding the mixture at 220 while the water boiled off. The final product was filtered with 5% Special Speed Flow filter aid. The yield was 360 parts or 90%. The product was clear, oil-soluble, and had an OD color of 820. The ash content was 20.02%, and the naphtha-insolubles 0.8% before filtering and 0.15% after filtering.

The base number of an SAE No. 20 mineral lubricating oil containing 3% of this product was 1.65. Thus the base number of the pure product was 55.

This product had a high alkaline reserve and was useful as a detergent additive for mineral lubricating oils for use in engines consuming high sulfur content fuels, such as diesel engines.

EXAMPLE II PREPARATION OF ADDrrIvE 6 oil base stock of 250 SSU at reaction vessel. temperature of 225 F. over a period of about one half. hour. A slurry consisting of 5.88 parts of phosphorus pentasulfide and about 12.3 parts of the Red Oil was slowly charged to the reaction vessel with stirring during a period of about forty-five minutes. After all of the phosphorus pentasulfide had been added, the mixture acquired a grayish color, which indicated that some phosphorus sulfide had not been dissolved. The mixture was held at 225 F. for approximately one hour, at the end of which time the mixture had turned dark brown and all of the phosphorus pentasulfide had disappeared. The product was filtered, using 2% by weight of special Speed Flow filter aid. The filtrate obtained had a saponification number of 70.6.

PREPARATION OF PRIMARY SAPONIFICATION PRODUCT The above product (84.2 parts) was charged to a reactor and heated to 150 F. Barium octahydrate (15.8 parts) was added slowly over a period of fifteen minutes. The mixture was heated to 215 F. and then to 250 F. for approximately one half hour. During the last ten minutes, the contents were air blown. Thereafter, the product was filtere with the aid of 5% Special Speed Flow filter aid. The product had an ash content of 13.3% and a saponification number of 23.4. A portion was reserved for testing.

PREPARATIoN OF SECONDARY SAPONIFICATION PRoDUcT The remainder of the primary saponification product was divided into several portions, and a number of secondary saponification products prepared to elucidate the chemical nature of the final reaction product of the invention.

It is evident that there are can be set forth as follows:

(1) A complex molecule in which the alkyl phenol, alkaline earth metal and phosphorus sulfide-degras reaction product all find a place, the alkyl phenol reacting as such with the primary saponification product so that a metal phenate does not play a part in the reaction mecha- 1118111.

(2) A complex molecule formed by reaction of the primary saponification product with alkaline earth metal phenate (the alkyl phenol reacting first with the alkaline earth metal compound). In this the presence of excess alkaline earth compound may or may not play a part.

(3) A mere mixture of net and metal phenate.

It is, of course, also of importance to show that the product of the invention differs from the completely saponified phosphorus sulfide-degras reaction product without alkyl phenol.

In the following, secondary saponification (SS) product No. 1 demonstrates that possibility No. 1) above is the correct interpretation of the data. SS products Nos. 2 and 3 below illustrate possibilities Nos. (2) and (3) above, and SS product No. 5 below shows the part played by excess alkaline earth metal compound in possibility No. (2). SS products Nos. 4a and 4b show the importance of the octyl phenol in the product of the invention.

several possibilities, which primary saponification mod 1. Secondary saponification product of the invention To one portion (79.7 parts) placed in a reaction vessel and heated to 150 F. were added 13.32 parts of barium octahydrate (Ba(OH)2-8H2O) over a period of fifteen minutes with stirring. Next, 6.9 parts of tertoctyl phenol were added and then the reaction mixture was heated to 300 R, which required one and one half hours. The final product was filtered with the aid of 5% Special Speed Flow filter aid. The product was clear, oil-soluble, had an OD color of 67.2, 20.1% ash, and a base number of 2.04 as a 4% solution in solvent extracted neutrol oil, 140 SSU. (Base number of pure product 51.)

2. Reaction product of primary saponification product and barium octyl phenate Another portion of the primary saponification product parts) was charged to a reaction vessel and heated F.), were charged to'a. The reaction mixture was brought to a.

prepared according to the procedure of U. S. Patent No. 2,362,291, was added. The reaction mixture was heated to 300 F. for one and one half hours and then filtered. A cloudy product was obtained having an OD color of 70.0 and 18.68% ash. On standing, a precipitate tended to settle at the bottom of the material. The material had a base number of 1.21 as a 4% solution in solvent extracted neutral oil, 140 SSU.

3. Mixture of primary saponification product and barium octyl phenate A mixture of barium octyl phenate parts) and the primary saponification product (90 parts) was prepared by blending the two products with stirring.

4. Completely saponified secondary saponification product without octyl phenol The third portion of the primary saponification product (91.9 parts) was charged to a reaction vessel and heated to 150 F. The amount of barium octahydrate theoretically required to bring the saponification number of the product to zero (1.8 parts barium octahydrate), was added over a period of fifteen minutes. The reaction mixture was heated to 300 F. for one and one half hours and then divided into three portions.

4a. Unfiltered One portion was reserved, unfiltered, for testing. It had a base number of 0.70 as a 4% solution in solventextracted neutral oil, 140 SSU, and was 18.0% ash.

4b. Filtered One portion was filtered. The filtrate was a clear material having an OD color of 59.8, an ash content of 15.53% and a base number of 0.60 as a 4% solution in solvent extracted neutral oil, 140 SSU.

5. Reaction product of 4a barium octyl phenate The third portion was not filtered. This product was cloudy and tended to form a precipitate on standing. The ash content was 18.0% and the base number 0.70 as a 4% solution in solvent-extracted neutral oil, 140 SSU. This product (90 parts) was charged to a reaction vessel and there was then added 10 parts of barium octyl phenate prepared according to U. S. Patent No. 2,362,391. The reaction mixture was heated to 300 F. for one and onehalf hours. The final product was cloudy and had an ash content of 19.15%. The base number was 1.30 gm IaT 4% solution in a solvent-extracted neutral oil, 140

All of these secondary saponification products were subjected to the Polyveriform test, with runs also being made on the base oil alone and on the primary saponification product for comparison. The following data was were too cloudy to run, the product being insoluble in oil. The filtered completely saponified primary reaction product and the two products made with barium octyl phenate are considerably inferior to the product of the invention in acid number, bearing corrosion and base number.

The above data also tends to show that the product of the invention is a complex reaction product of the phosphorus sulfide-degras reaction product, with the alkaline earth metal and the alkyl phenol actually in the molecule in some way. The product of the invention has properties distinguishing it from and superior to mixtures of the phosphorus su1fide-degras metal derivative and metal alkyl phenate (SS No. 3 in the table), reaction product of the completely saponified metal derivative and metal alkyl phenate (SS No. 5 in the table) and reaction product of the partially saponified metal derivative and metal alkyl phenate (SS N0. 2 in the table). All of the latter materials could be regarded as possible products of the invention, as pointed out above, but the data tends to disprove their existence, and suggests that the order of reaction of the components in the process of the invention is critical from the standpoint of the superior characteristics of the product produced, even though its structure remains unknown.

The additive of the invention with an oxidation inhibitor was subjected to an Ethyl Engine operation for sixty hours following Procedure VI.

This is a test which simulates heavy duty service. The operating conditions were as follows:

Type of engine, Ethyl series 30 Engine speed, 1200 R. P. M. Sump temperature, 300 F. Jacket temperature, 350 F. Air-fuel ratio, 12:1 Compression ratio, 7:1 Catalyst, none The following data was obtained:

TABLE II Additive of the Invention plus 1% Oxidation Inhibitor B Percent Additive. 4.0 4 0 Percent Sludge Percent Pentaue Ins 0.132 0.122 Acid Number 2.18 2.06 Viscosity Increase" 111 105 Piston Skirt 1. 0 1. 5 Condition of Rings F+C F+C Demerit Rating 4.4 4.7 Bearing Loss, mgs 76 66 1 OPS No. 69 (a commercial sulfurized terpene lubricating oil additive).

obtained: 2 Condition of rings: F+C=Free and Clear.

TABLE I P1i3dtl0tlf the R i Reaction prodnven on eact on not of barium Reaetionprodproduct of gimg g zg ggggfgggg Filtered comoctyl phenate Base Primary not of primary barium octyl phenate with sanonified plctely saponiand unfiltered Oil saponification sapomficat on phenate and primary phmar fied primary completely Product product with primary saponification saponificgion saponification saponified barium hysaponification product roduct product primary droxide and product p saponification octyl phenol product SS 3 5. Percent AdditlVtL 4.0%.

rity Cloud t. on Color Cloud? pp Base Number T00 Bearing Corrosion, Mg. cloudy Loss. to run Lacquer Rating, Steel. ppt Sludge Rating, Glass in Percent Sludge.. bottom 0.08. Acid Number. 5.76. Viscosity Increase The above data shows that the additive of the invention in combination with an oxidation inhibitor produces a lubricant having good antioxidant and detergent balance.

The composition containing the additive of the invention plus oxidation inhibitor B was further subjected to the Chevrolet engine L-4 test.

The engine used for this test is a standard 6-cylinder (3 /2" bore by 3%" stroke) overhead valve Chevrolet engine and the L-4 test procedure is given CRC desig-' nation L-4-545. The test results obtained were as follows, for an SAE No. 20 acid-treated mineral lubricating oil containing 4% of the additive of the invention and 1% of oxidation inhibitor B TABLE III 5 Gold surface:

Rocker arms 1. 50 Side pan 1. 00 Valve cover 0. 25

il Pan:

0. 85 0.25 Piston skirts 0. 00 Piston and Rings 0. 25 Used oil analysis" Vis/100. 413 eut. No.. 1.37 Percent sludge (1180).. 0. 60 Percent asph. (HSC) D. 10 Vis. incr 28 Average 0. 69 Bearing loss (Avg.) mgms 31.9 Corrosion demerit- 0. 32 Appearance:

Std 95. 5 Fuel:

Composition L-4 New oil analysis:

L-4 Ratin Sludge deposit:

Rocker arm assembly 8.

asses? 8888888 888888 Combined engine-deposit rating for varnish and sludge Bearing weight loss:

This test shows the oil to be excellent both in detergcncy and in oxidation inhibition. The demerit rating is unusually low.

The additive of the invention can be added to a mineral lubricating oil at any concentration desired, depending upon the type of service. Generally, from 2 to 6% additive by weight of the oil is added. Diesel engines operating on fuels containing 0.5% sulfur and above provide the severest conditions and will require the largest amount of the additive, while automobile engines provide mild conditions so that smaller amounts of additive can be used. It is advisable to employ the additive of the invention in conjunction with an antioxidant to provide protection for copper-lead bearings.

All parts and percentages in the specification are by weight. Base numbers as referred to in the specification are determined in accordance with ASTM D664-46T. saponification numbers are determined in accordance with ASTM D94-48T.

We claim:

1. A process of preparing an oil-soluble lubricating oil detergent additive characterized by a high alkaline reserve comprising reacting a phosphorus sulfide and degras at a reaction temperature below sludge formation to form an acidic reaction product, reacting the product with an alkaline earth compound in an amount to partially saponify the product and then reacting the resulting partially saponified product with an alkyl phenol and an alkaline earth compound to further saponify the product and efiect an increase in its base number to obtain an alkaline reaction product having a high base number.

2. A process of preparing an oil-soluble lubricating oil detergent additive characterized by a high alkaline reserve comprising reacting a phosphorus sulfide and degras in the presence of a diluent at a reaction temperature below sludge formation to form an acidic reaction product, reacting the product with an alkaline earth hydroxide in an amount to partially saponify the product and then reacting the resulting partially saponified product with an alkyl phenol and an alkaline earth hydroxide to further saponify the product and effect an increase in its base number to obtain an alkaline reaction product having a high base number.

3. A process of preparing an oil-soluble lubricating oil detergent additive characterized by a high alkaline reserve comprising reacting a phosphorus sulfide and degras at a temperature below about 250 F. to form an acidic reaction product, reacting the product with an alkaline earth hydroxide in an amount to partially saponify the product and then reacting the resulting partially saponified product with an alkyl phenol and an alkaline earth hydroxide to further saponify the product and effect an increase in its base number to obtain an alkaline reaction product having a high base number.

4. An oil-soluble lubricating oil detergent additive having a high alkaline reserve adapting it for use in engines consuming high sulfur content fuels comprising the second stage saponification product of an alkyl phenol, an alkaline earth hydroxide and the primary partial saponification product of an alkaline earth hydroxide and the product of the reaction at a temperature below sludge formation of a phosphorus sulfide and degras.

5. A reaction product in accordance with claim 4 in which the phosphorus sulfide is phosphorus pentasulfide.

6. A reaction product in accordance with claim 4 in which the alkaline earth hydroxide is barium hydroxide.

7. A reaction product in accordance with claim 4 in which the alkaline earth hydroxide is calcium hydroxide.

8. A reaction product in accordance with claim 4 in which the alkyl phenol is octyl phenol.

9. A reaction product in accordance with claim 8 in which the octyl phenol is tert-octyl phenol.

10. A mineral oil lubricant having a high alkaline reserve adapting it for use in engines consuming high sulfur content fuels, comprising a large proportion of a mineral lubricating oil and a small amount of an oil-soluble lubricating oil detergent additive comprising the second stage saponification product of an alkyl phenol, an alkaline earth hydroxide and the primary partial saponification product of an alkaline earth hydroxide and the product of the reaction at a temperature below sludge formation of a phosphorus sulfide and degras.

11. A mineral oil lubricant in accordance with claim 10 in which the additive is the second stage saponification product of an alkyl phenol, barium hydroxide and the primary partial saponification product of barium hydroxide and the product of the reaction of phosphorus pentasulfide and degras.

12. A mineral oil lubricant in accordance with claim 10 in which the additive is the second stage saponification product of an octyl phenol, barium hydroxide and the primary partial saponification product of barium hydroxide and the product of the reaction of phosphorus pentasulfide and degras.

13. A mineral oil lubricant having a high alkaline reserve adapting it for use in engines consuming high sulfor content fuels, comprising a large proportion of a mineral lubricating oil, a small amount of an anti-oxidant lubricating oil additive and a small amount of an oilsoluble lubricating oil detergent additive comprising the second stage saponification product of an alkyl phenol, an alkaline earth hydroxide and the primary partial saponification product of an alkaline earth hydroxide and the product of the reaction at a temperature below sludge formation of a phosphorus sulfide and degras.

14. A mineral oil lubricant in accordance with claim 13 in which the detergent additive is the second stage saponification product of an alkyl phenol, barium hydroxide and the primary partial saponification product of barium hydroxide and the product of the reaction of phosphorus pentasulfide and degras.

15. A mineral oil lubricant in accordance with claim 13 in which the detergent additive is the second stage saponification product of an octyl phenol, barium hydroxide and the primary partial saponification product of barium hydroxide and the product of the reaction of phosphorus pentasulfide and degras.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,274,302 Mulit Feb. 24, 1942 2,361,746 Cook Oct. 31, 1944 2,375,061 Williams May 1, 1945 2,616,911 Asself Nov. 4, 1952 

4. AN OIL-SOLUBLE LUBRICATING OIL DETERGENT ADDITIVE HAVING A HIGH RESERVE ADAPTING IT FOR USE IN ENGINES CONSUMING HIGH SULFUR CONTENT FUELS COMPRISING THE SECOND STAGE SAPONIFICATION PRODUCT OF AN ALKYL PHENOL, AN ALKALINE EARTH HYDROXIDE AND THE PRIMARY PARTIAL SAPONIFICATION PRODUCT OF AN ALKALINE EARTH HYDROXIDE AND THE PRODUCT OF THE REACTION AT A TEMPERATURE BELOW SLUDGE FORMATION OF A PHOSPHORUS SULFIDE AND DEGRAS. 